Drop-shutter for cameras



(No Model.)

L. A. DE RIBAS.

DROP SHUTTER FOR GAMERAS.

No. 359,715. Patented Ma'r. 22, 1887.-

g m \\\\\\\\\w \\\\\\\\\\\\\\\\\\\\\\\u m u lg g UNITED STATES PATENTOFFICE.

LOUIS A. on RIBAS, or BOSTON, MASSACHUSETTS.

DROP-SHUTTER FOR CAM ERAS.

SPECIFICATION forming part of Letters Patent No. 359,715, dated March22, 1887.

Application filed October 30, 1886. Serial No. 217,568. (No model.)

To all whom it may concern.-

Be it known that I, LOUIs A. DE RIBAS, a

citizen of the United States, and a resident of Boston, in the county ofSuffolk and State of Massachusetts, have invented new and usefulImprovements in Drop-Shutters for Cameras, of which the following, takenin connection with the accompanying drawings, is a specifi cation.

This invention relates to improvements in drop-shutters for photographiccameras, and it is carried out as follows, reference being had to theaccompanying drawings, where Figure 1 represents a front elevation ofthe invention, and Fig. 2 represents a cross-section on the line .A B,shown in Fig. 1. Fig. 3 represents a cross-section on the line C D, alsoshown in Fig. 1.

7 Similar letters refer to similar parts wherever they OGGJI' on thedifferent parts of the drawings.

a is the circular block or case, provided between its center and outerperiphery with a cylindrical perforatioma, into which the Outer ring ofthe lens is inserted when the shutter is to be used. The'circular blockor case a has on its face an annular projection, a", to which is securedin a suitable manner the cover Z), as shown in the drawings.

In the circular space between the front of the block or case a and itscover I) is loosely arranged the circular shutter c, which latter ispivoted in its center to the center of the case a and cover I) by meansof the pin d,that passes loosely through the case a and cover I), and issuitably attached to the circular shutter 0.

c is a perforation in the shutter c, which perforation is of a suitablesize and shape, according to the amount of exposure that may be requiredin taking the desired view or object. To the outside of the circularshutter c is secured a small block or lock-piece, c, having lockingprojections c and c, as shown in Figs.1 and 2. The cover bhas asemicircular, or nearly so,cut-away portion, 1), and concentric slots 22and b communicating with the said cut-away portion 1), as shown in thedrawings.

To the front of cover b, near its slot b are secured the bearings e ande, in which is journaled the small pin or shaft f, terminating outsideof the case a as a crank or lever, f. (Shown in Figs. 1 and 3.) The pinor shaft f has on its under side a locking'tooth, f, adapted to hold theshutter 0 in a closed position when it is swung to the limit of itsstroke in an opposite direction to the arrow shown in Fig. 1, and insuchclosed position the block a is swung backward sufficiently to enterthe slot b the tooth f passing between the looking projections c 0"v andresting against the projection c". In such locked or closed position ofthe shutter the crank or lever f is prevented from swinging back of thecover I) by resting against the stationary pin Or projection secured tocover I) or its case a, as shown in Figs. 1 and 3.

The adjustable mechanism for turning the shutter a quickly around itsaxis as soon as released is carried out as follows: On the "front end ofthe central pin, cl, is wound and secured the cord, flat spring, or wireh, the lower end of which is secured to the upper end of the spiralspring (or elastic) h, as shown in Figs. 1 and 2.

To the lower end of spring h is connected the upper end of theregulating-screw i, preferably by means of a rod or wire, i, made in onepiece or connected to the screw t, the upper portion of which wire 1"passes loosely through the swivel 7r, that is located within the springh, as shown in Figs. 1 and 2, the wire t" having a head in its upper endresting on top of the swivel k, and the latter resting in its lower endon the lower portion of the spiral spring h, by which arrangement thescrew i may be turned around its axis without turning the spring 71. orthe connection h.

Z is a nut in which the screw i works, such nut being secured to thecover I), and the lower portion of said screw is preferably guided inthe perforated bearing-piece m, secured to case a or' its cover I), asshown in Figs. 1 and 2.

z' is a serrated knob or thumb-piece in the lower end of the screw i, asshown in Figs. 1 and 2, by means of which the screw i can be regulatedto adjust the power of the spring h,

IOO

stroke, and it is then prevented from-rebounding by the spring a,(secured to cover 2),) the free end of which looks against theprojection c on block 0, after such projection has passed by the freeyielding end of said spring 12.

The operation is as follows: According to the velocity with which theshutter c is to act the tension of the spring h is regulated by means ofthe screw 73, as above described. The shutter c is then turned aroundits axis in a direction opposite to that indicated by arrow in Fig. 1,until the projection c on block 0 has passed by the tooth f on the pinor shaft f, by which the shutter c is held locked in a closed position.Vhen it is desired to take the picture, the operator swings the crank orleverf in the direction of the arrow shown in Fig. 8, thereby causingthe tooth f to pass by the projection c and release the shutter c, whichis instantly turned around its axis in the direction shown by arrow inFig. 1, and during such movement of the shutter its perforation c for amoment coincides with the case or lens opening a, and as quickly closesthe latter. The block 0 during the closing motion enters the curved slotb, butts against the bunter I)", and is automatic ally held at the limitof its stroke by the spring a, as above described.

Should it be desired to actuate the shutter c in a reverse direction tothe one above described, it is only necessary to wind the cord hin anopposite direction on the pin d and to add a locking-spring, 0, near theslot If, as shown in Fig. 1, such spring when in use being liberatedfrom the pin or catch 0,that otherwise holds it in inoperative position.When using the shutter in this manner, it is moved in the direction ofthe arrow shown in Fig. 1 until the block 0 reaches the hunter '1) andthe spring a locks it against the power of the spring 71/. hen thepicture is to be taken, the lockingspring a is depressed, when theshutter is swung in a direction opposite to the arrow shown in Fig. 1,by the influence of spring h, until the block 0 reaches the limit of itsstroke in the slot b, and there caused to be automaticallylocked andheld by the spring 0 and projection c 011 block a.

This my improved drop shutter is very light and simple in construction,is easily set and operated, and can readily be adj ustcd for varyingvelocities of exposure, as may be desired for quick and slow plates, ormore or less light objects that are to be photographed.

Having thus fully described the nature,construction, and operation of myinvention, I wish to secure by Letters Patent, and clain1- In adrop-shutter, the perforated case a a and cover I), having cut-awayportion b and curved slots 1/ b,in combination with the perforatedshutter c c, pivoted to the said case and cover, the block andprojections c c 0* on the shutter, the holding and releasing device fff, spring a, the adjustable regulating-screw 1', spring 7i, andconnection h to the shutterspindle, as and for the purpose set forth.

In testimony whereof I have signed my name to this specilicatiomin thepresence of two subscribing witnesses, on this 25th day ol'Octoher, A.I). 1886.

LOUIS A. DE RTBAS.

Witnesses:

ALBAN Annnnx, HENRY CHADIBOURN.

